Attachment 25629 Details for Bug 49481 – RAD's OutputStreamWriter

RAD's OutputStreamWriter

OutputStreamWriter.java (text/plain), 12.94 KB, created by Richard on 2010-06-22 14:15:41 UTC

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Creator: Richard

Created: 2010-06-22 14:15:41 UTC

Size: 12.94 KB

patch

obsolete

>/*
> * @(#)OutputStreamWriter.java	1.50 06/06/07
> *
> * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
> * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
> */
>
>package java.io;
>
>import java.nio.charset.Charset;
>import java.nio.charset.CharsetEncoder;
>import sun.nio.cs.StreamEncoder;
>
>
>/**
> * An OutputStreamWriter is a bridge from character streams to byte streams:
> * Characters written to it are encoded into bytes using a specified {@link
> * java.nio.charset.Charset <code>charset</code>}. The charset that it uses
> * may be specified by name or may be given explicitly, or the platform's
> * default charset may be accepted.
> *
> * Each invocation of a write() method causes the encoding converter to be
> * invoked on the given character(s). The resulting bytes are accumulated in a
> * buffer before being written to the underlying output stream. The size of
> * this buffer may be specified, but by default it is large enough for most
> * purposes. Note that the characters passed to the write() methods are not
> * buffered.
> *
> * For top efficiency, consider wrapping an OutputStreamWriter within a
> * BufferedWriter so as to avoid frequent converter invocations. For example:
> *
> * <pre>
> * Writer out
> * = new BufferedWriter(new OutputStreamWriter(System.out));
> * </pre>
> *
> * A surrogate pair is a character represented by a sequence of two
> * <tt>char</tt> values: A high surrogate in the range '&#92;uD800' to
> * '&#92;uDBFF' followed by a low surrogate in the range '&#92;uDC00' to
> * '&#92;uDFFF'. 
> *
> * A malformed surrogate element is a high surrogate that is not
> * followed by a low surrogate or a low surrogate that is not preceded by a
> * high surrogate. 
> * 
> * This class always replaces malformed surrogate elements and unmappable
> * character sequences with the charset's default substitution sequence.
> * The {@linkplain java.nio.charset.CharsetEncoder} class should be used when more
> * control over the encoding process is required.
> *
> * @see BufferedWriter
> * @see OutputStream
> * @see java.nio.charset.Charset
> *
> * @version 	1.50, 06/06/07
> * @author	Mark Reinhold
> * @since	JDK1.1
> */
>
>public class OutputStreamWriter extends Writer {
>
>	// New variables for caching writes //IBM-perf_ShortString
>	private static final int BUFFER_SIZE = 512; //IBM-perf_ShortString
>	private OutputStreamWriter osw = null;		//output stream writer to wrap //IBM-perf_ShortString
>	private char[] buffer = new char[BUFFER_SIZE]; //IBM-perf_ShortString
>	private volatile int index = -1; //IBM-perf_ShortString
>	private volatile boolean streamClosed = false; //IBM-perf_ShortString
>	private boolean bufferFlushed = true; //IBM-perf_ShortString
> //IBM-perf_ShortString
>	private final StreamEncoder se; //IBM-perf_ShortString
>
> /**
> * Creates an OutputStreamWriter that uses the named charset.
> *
> * @param out
> * An OutputStream
> *
> * @param charsetName
> * The name of a supported
> * {@link java.nio.charset.Charset </code>charset<code>}
> *
> * @exception UnsupportedEncodingException
> * If the named encoding is not supported
> */
> public OutputStreamWriter(OutputStream out, String charsetName)
>	throws UnsupportedEncodingException
> {
>	super(out);
>	if (charsetName == null)
>	 throw new NullPointerException("charsetName");
>	se = StreamEncoder.forOutputStreamWriter(out, this, charsetName);
> }
>
> /**
> * Creates an OutputStreamWriter that uses the default character encoding.
> *
> * @param out An OutputStream
> */
> public OutputStreamWriter(OutputStream out) {
>	super(out);
>	try {
>	 se = StreamEncoder.forOutputStreamWriter(out, this, (String)null);
>	} catch (UnsupportedEncodingException e) {
>	 throw new Error(e);
> }
> }
>
> /**
> * Creates an OutputStreamWriter that uses the given charset. 
> *
> * @param out
> * An OutputStream
> *
> * @param cs
> * A charset
> *
> * @since 1.4
> * @spec JSR-51
> */
> public OutputStreamWriter(OutputStream out, Charset cs) {
>	super(out);
>	if (cs == null)
>	 throw new NullPointerException("charset");
>	se = StreamEncoder.forOutputStreamWriter(out, this, cs);
> }
>
> /**
> * Creates an OutputStreamWriter that uses the given charset encoder. 
> *
> * @param out
> * An OutputStream
> *
> * @param enc
> * A charset encoder
> *
> * @since 1.4
> * @spec JSR-51
> */
> public OutputStreamWriter(OutputStream out, CharsetEncoder enc) {
>	super(out);
>	if (enc == null)
>	 throw new NullPointerException("charset encoder");
>	se = StreamEncoder.forOutputStreamWriter(out, this, enc);
> }
>
> /**
> * Returns the name of the character encoding being used by this stream.
> *
> * If the encoding has an historical name then that name is returned;
> * otherwise the encoding's canonical name is returned.
> *
> * If this instance was created with the {@link
> * #OutputStreamWriter(OutputStream, String)} constructor then the returned
> * name, being unique for the encoding, may differ from the name passed to
> * the constructor. This method may return <tt>null</tt> if the stream has
> * been closed. 
> *
> * @return The historical name of this encoding, or possibly
> * <code>null</code> if the stream has been closed
> *
> * @see java.nio.charset.Charset
> *
> * @revised 1.4
> * @spec JSR-51
> */
> public String getEncoding() {
>	return se.getEncoding();
> }
>
> /**
> * Flushes the output buffer to the underlying byte stream, without flushing
> * the byte stream itself. This method is non-private only so that it may
> * be invoked by PrintStream.
> */
> void flushBuffer() throws IOException {
>	se.flushBuffer();
> }
>
> /**
> * Writes a single character.
> *
> * @exception IOException If an I/O error occurs
> */
> public void write(int c) throws IOException {
> 	synchronized (lock) { //IBM-perf_ShortString
> 		if (!bufferFlushed) //IBM-perf_ShortString
> 			if(1 >= (BUFFER_SIZE - index)) {	//no space left in buffer, so write existing contents //IBM-perf_ShortString
> 				emptyBuffer(); //IBM-perf_ShortString
> 			} //IBM-perf_ShortString
> 		 //IBM-perf_ShortString
> 		if(1 > BUFFER_SIZE || streamClosed) { //IBM-perf_ShortString
> 			se.write(c); //IBM-perf_ShortString
> 			return; //IBM-perf_ShortString
> 		} //IBM-perf_ShortString
> 		bufferFlushed = false; //IBM-perf_ShortString
> 		buffer[++index] = (char)c; //IBM-perf_ShortString
> 	} //IBM-perf_ShortString
> 	 //IBM-perf_ShortString
> }
> //IBM-perf_ShortString
> /**
> * Writes a portion of an array of characters.
> *
> * @param cbuf Buffer of characters
> * @param off Offset from which to start writing characters
> * @param len Number of characters to write
> *
> * @exception IOException If an I/O error occurs
> */
> public void write(char cbuf[], int off, int len) throws IOException {
> 	synchronized (lock) { //IBM-perf_ShortString
> 		if (!bufferFlushed) //IBM-perf_ShortString
> 			if(cbuf.length >= (BUFFER_SIZE - index)) {	//no space left in buffer, so write existing contents //IBM-perf_ShortString
> 				emptyBuffer(); //IBM-perf_ShortString
> 			} //IBM-perf_ShortString
> 		 //IBM-perf_ShortString
> 		if(cbuf.length > BUFFER_SIZE || streamClosed) { //IBM-perf_ShortString
> 			se.write(cbuf, off, len); //IBM-perf_ShortString
> 			return; //IBM-perf_ShortString
> 		} //IBM-perf_ShortString
> 		bufferFlushed = false; //IBM-perf_ShortString
> 		System.arraycopy(cbuf, off, buffer, index + 1, len); //IBM-perf_ShortString
> 		index += len ;		//set position for next writing //IBM-perf_ShortString
> 	} //IBM-perf_ShortString
> }
>
> /**
> * Writes a portion of a string.
> *
> * @param str A String
> * @param off Offset from which to start writing characters
> * @param len Number of characters to write
> *
> * @exception IOException If an I/O error occurs
> */
> public void write(String str, int off, int len) throws IOException {
> 	synchronized (lock) { //IBM-perf_ShortString
> 		if (!bufferFlushed) //IBM-perf_ShortString
> 			if(str.length() >= (BUFFER_SIZE - index)) { //no space left in buffer, so write existing contents //IBM-perf_ShortString
> 				emptyBuffer(); //IBM-perf_ShortString
> 			} //IBM-perf_ShortString
> 		 //IBM-perf_ShortString
> 		if(str.length() > BUFFER_SIZE || streamClosed) { //IBM-perf_ShortString
> 			se.write(str, off, len); //IBM-perf_ShortString
> 			return; //IBM-perf_ShortString
> 		} //IBM-perf_ShortString
> 		 //IBM-perf_ShortString
> 		bufferFlushed = false; //IBM-perf_ShortString
> 		char[] cbuf=str.toCharArray(); //IBM-perf_ShortString
> 		System.arraycopy(cbuf, off, buffer, index+1, len); //IBM-perf_ShortString
> 		index += len ; //set position for next writing //IBM-perf_ShortString
> 	} //IBM-perf_ShortString
> }
>
> /**
> * Flushes the stream.
> *
> * @exception IOException If an I/O error occurs
> */
> public void flush() throws IOException {
>		synchronized (lock) { //IBM-perf_ShortString
>			emptyBuffer(); //IBM-perf_ShortString
>			se.flush(); //IBM-perf_ShortString
>		} //IBM-perf_ShortString
> }
>
> public void close() throws IOException {
>		synchronized (lock) { //IBM-perf_ShortString
>			emptyBuffer(); //IBM-perf_ShortString
>			streamClosed = true; //IBM-perf_ShortString
>			se.close(); //IBM-perf_ShortString
>		} //IBM-perf_ShortString
> }
> //IBM-perf_ShortString
>	private void emptyBuffer() throws IOException { //IBM-perf_ShortString
>		synchronized (lock) { //IBM-perf_ShortString
>			bufferFlushed = true; //IBM-perf_ShortString
>			if (!streamClosed) //IBM-perf_ShortString
>				se.write(buffer, 0, index + 1); //IBM-perf_ShortString
>			index = -1; //IBM-perf_ShortString
>		} //IBM-perf_ShortString
>	} //IBM-perf_ShortString
>}
>//IBM-perf_ShortString

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Attachments on bug 49481: 25625 | 25629